OBJECT DRUGS

Anticoagulants, Oral:

• Acenocoumarol
• Warfarin (Coumadin, etc.)

PRECIPITANT DRUGS

HMG CoA Reductase Inhibitors:

• Fluvastatin (Lescol, etc.)
• Lovastatin (Mevacor, etc.)
• Rosuvastatin (Crestor)
• Simvastatin (Zocor)

Comment:

Fluvastatin inhibits CYP2C9 while lovastatin and simvastatin may inhibit CYP3A4 and could increase the hypoprothrombinemic response to warfarin in some patients. Rosuvastatin has been noted to increase the INR in patients taking warfarin.

Class 3: Assess Risk & Take Action if Necessary

• Consider Alternative: Other HMG CoA reductase inhibitors such as pitavastatin (Livalo), pravastatin (Pravachol) and atorvastatin (Lipitor) appear to have little or no effect on warfarin response.
• Monitor: Monitor for altered warfarin response if fluvastatin, lovastatin, rosuvastatin, or simvastatin are initiated, discontinued, or changed in dosage.